Vitamin k - 701 LEAP5 ™

Top line new vitamin k - 701 LEAP5 ™ sulfuric acid catalyst meet SO in the future₂Emissions standards.

launch
Cesium promote vanadium catalyst (in the late 1980 s has listed) has proved that we can very effectively reduce to use highly active in low temperature sulfuric acid device SO₂Emissions.

In 1996, the top line introduced a vitamin k - 69 catalyst, used in [1, 2] two turn two suction device in the operation of the last few paragraphs.Compared to the cesium potassium promote catalyst and early promote catalyst, the catalyst has very significant activity.Through the existing 3:1 two turning two suction devices in the last paragraph loading vitamin k - 69, SO₂Emissions can be cut in half, or 15-20% of acid productivity without increasing the SO₂Emissions.Use VK69 two turned two suction device, SO₂Emissions below 100 PPM has become possible.

But, more stringent regulation of sulfuric acidIndustry to reduce the SO₂There has been a new emissions requirements, and make the two turning two suction device conversion range is usually 99.8 99.95% (0.3-1.3 kg SO₂MT/H.₂SO₄, 0.7 to 2.6 LBS/ST), while a turn a suction device is greater than 98-99% (6.5-13 kg SO₂MT/H.₂SO₄And 13 to 26 LBS/ST).In terms of many existing device, low emission limit value productivity is a challenge to them now or in the future.

Top line to the new market demand have to respond, is committed to developing a new type of catalyst dedicated to low temperature high concentration gas conversion vitamin k - 701 LEAP5 ™.The new catalyst has high activity, can make a turn a suction or two turn two suction device to SO₂Industrial emissions standards.

background

Commercial sulfuric acid catalyst for vanadium oxide matrix, useWith inert porous silica as the support body of alkali metal sulfate as additives.The liquid phase (SLP) catalyst, catalyst belongs to load SO₂The oxidation of liquid film on the surface of the inside cover support material in the form of a homogeneous reaction occurred in.

Alkali metal additives mainly potassiumAnd sodium, but due to the excellent low temperature activity, cesium is also used toSome of the catalyst.Despite of the catalytic melt and the reaction mechanism of coordination chemistry has a lot of research and publications, but it is not entirely clear details of the mechanism.However, a lot of evidence that, in the performance of two polyethylene oxide vulcanization vanadium catalytic cycle is only in the form of [3] oxidation state V5 + for the activity.

Under steady state, the formation and distribution of vanadium in catalytic melts in the certain V5 +, V4 + and the surrounding gas of V3 + balance.However, V4 +
And the V3 + compounds on catalytic activity and no boost.At low temperatures and high SO₂Partial pressure reduction degree increase, in addition, some V4 +
Compounds at temperature below 460 ℃ (860 ° F) precipitation occurs, if the temperature is further reduced, will gradually exhausted V5 + melt.For standard potassium for vanadium catalyst, at about 360 ° C (680 ° F), in some of the lowest temperature of the reduction and local solidification will eventually lead to fall to almost zero.

Catalyst reaction rate can be passed through the external quality and toParticles on the surface of the heat, and the internal quality through the porous support exchange or to limit the intrinsic reaction rate.For operation under high gas concentration and low temperature of sulfuric acid catalyst, the main limitation is the intrinsic reaction rate.Intrinsic reaction rate depends on the chemistry, catalyst melt to a great extent, but also depends on the support on the catalytic melt and the distribution of gas solubility, and through the traffic status of the melt.Under steady state, the physical distribution of the melt and its surrounding gas balance, the distribution depends on the nanoscale silicon support body surface features, such as wettability and surface tension.For existing commercial sulfuric acid catalyst, active catalytic melt deep pool severely restricted, and the molten pool also hinder the transfer of gas in the active phase.

Top line has developed called vitamin k - 701 - a new catalyst, it is based on our new LEAP5 ™ technology, able to overcome these limitations, and have good activity.In addition to its high V5 + content, the improvement also reflects in:

• Change the internal shape and surface characteristic of the carrier.
• For high SO_{The optimization of the active phase 3 concentration}.

First of all, according to the new formula has confirmed that highly active new catalyst for the laboratory tests,Then continue production and test of middle and small scale.A large number of test again reflects the excellent activity and mechanical strength of products and the pressure drop and stability.We install and optimized the one used in the manufacture of new type LEAP5 ™ technology unique new catalyst for the production line.Through a comprehensive production, vitamin k - 701 product all the performance parameters are confirmed.

Vitamin k - 701 LEAP5 ™The characteristics and performance

New vitamin k - 701 LEAP5 ™ designed for use in strong concentrations in the conversion of gas to run at low temperature.The catalyst is shown in figure 2, its features summarized as follows:

Catalyst name: vitamin k - 701 LEAP5 ™
Size and shape: 12 mm daisies
Application: a turn of a suction device after few paragraphs;3-1 and 3-2 two turns to the third paragraph of suction device
Operating temperature: 400-500 ° C (750-930 ° F),
The light-off temperature: 310 ° C (590 ° F)
Thermal stability: 650 ° C ° C (1200 ° F)

The choice of the particle size is the result of the activity and the pressure drop for compromise.Pore diffusion limit in the high concentration of reformed gas moderate, as a result, vitamin k - 701 according to the standard size of 12 mm Daisy form, the pressure drop is lower than 9 mm Daisy form.High unit bed pressure drop equal to the well-known image of 12 mm Daisy products (vitamin k - 38, vitamin k - 48, and vitamin k - 59) the pressure drop.Because vitamin k - 701 catalyst components based on the well-known sulfuric acid catalyst materials, so waste catalyst is very easy to handle.

In contains 10%.so₂And 10% O₂Run in the feed gas with high conversion rate of the activity of vitamin k - 701 from the perspective of the temperature change and the traditional top line products vitamin k - 48 and vitamin k - 59 comparison.Compared with the standard potassium promote vitamin k - 48, vitamin k - 59 at the temperature below 430 ℃ (805 ° F) due to its content of cesium and make the activity has improved significantly.However, the new type of vitamin k - 701 in the whole temperature range is twice as tall as the activity of vitamin k - 59.

High levels of V5 +

LEAP5 ™ technology is a major leap is catalytic melt oxidation state of vanadium in the V5 + high levels.Vitamin k - 701 has high vanadium content, but compared with other commercial catalyst, not much higher.However, once the running in gear, reactive melt will adjust to the chemical components and the surrounding gas conditions.In order to further study this balance, we have measured in the laboratory for different content of vanadium oxidation state.We will be the catalyst samples crushing and screening 1-2 mm diameter.Then the particle loading into the isothermal glass reactor, and contains 10%.so₂
And 10% O₂In the feed gas.Run after 1 days, in the heart of the nitrogen samples rapid quenching to room temperature, then the three-step REDOX titration analysis V5 +, V4 + and the content of V3 +.

The results show that under these conditions the three oxidation state,Although the V3 + content is very low.Vitamin k - 48 standard catalyst when temperature is 380-440 ℃ contain some active V5 +, but the majority of vanadium is actually the deactivation V4 + and the V3 + form.Cesium promote VK59 catalyst reduction of vanadium containing less, but the content of the V5 +
The same as the vitamin k - 48.When temperature is 380-400 ℃, the content of the V5 + the lowest in the three kinds of catalysts, because V5 + has been SO₂Restore a V3 + and V4 +.Vitamin k - 701 LEAP5 ™ is different.When temperature is 400-440 ° C, the activity of the catalyst vanadium V5 + content is very high, about 70% of the total vanadium content.The activity of vitamin k - 701 vanadium content is higher than the existing commercial catalysts on the market of the two to three times.

Vitamin k - 701 LEAP5 ™ operating experience

Vitamin k - 701 industrial application for the first time was a turn in the western countries the sulfur absorption device.SO₂Converter contains five catalyst bed layer, the first bed layer and the second bed by indirect cooling, between the second bed layer and layer 3 bed after using air quench.There is no cooling bed 4 and 5 bed layer.The raw material of the converter gas containing 8.8%.so₂And 12% of O₂.

During a 2010 parking, vitamin k and vitamin k - 59-48 catalysts in the last few paragraphs are replaced with volume such as vitamin k - 701, in order to reduce the SO₂Emissions and increase productivity.Before filling vitamin k - 701, in the fourth bed inlet temperature is about 420 ℃ (788 ° F), the total conversion rate was 98.77%, (about 1000 parts per million (PPM) SO in the feed gas₂), under the condition of the device according to the 245 MTPD run the productivity of STPD (270).

After the start to run the test, at the same time analysis the SO₂And O_{The content of 2,}And bed inlet and outlet temperature measurement.More gas and temperature measurement show that 4 bed inlet cold snap in performance is significantly influenced by the incomplete mixing.However, the fifth bed similar measurement shows that gas composition was homogeneous.

Inlet temperature to 404 ℃ (760 ° F), fill in the last few paragraphs 26.4 m3 vitamin k - 701, SO in the feed gas₂The concentration of the
Have decreased to about 720 PPM, productivity rose to 266 MTPD STPD (293).As a result, the new type of vitamin k - 701 instead of vitamin k - 59 and vitamin k - SO 48 can reduce 20%₂SO emissions in kilograms₂H/metric ton₂SO₄, and increased productivity by 9%
.We can see, even if there are 4 bed mixed problem of active vitamin k - 701 is twice of the new type of vitamin k - 59.

advantages

Oxidation state the increase in content of vanadium V5 + vitamin k - 701 LEAP5 ™ activity in the whole temperature range are higher than vitamin k - 48 and vitamin k - 59.Vitamin k - 701 LEAP5 ™ with 12 mm daisies in the shape of a top line standard delivery, to ensure that the low pressure drop.

conclusion

Top line has been reduced SO on sulfuric acid industry₂Request to make the response, developed a new type of sulfuric acid catalyst: vitamin k - 701 LEAP5 ™.The catalyst is based on our LEAP5 ™, for the development of new technology and to overcome the existing commercial sulfuric acid catalyst melt transport defect of active phase.Compared with other industrial catalyst, contains vitamin k - 701 V5 + form active vanadium two to three times more, so, it is changed in the high concentration of gas with high activity and low temperature.

In the last bed filling vitamin k - 701, after the fourth bed SO turn in a sulfuric acid absorption device₂Emissions compared with cesium promote catalyst, can reduce 20-30%, compared with the standard potassium promote catalyst, can reduce 30-40%.In the third period of loading 3:1 device vitamin k - 701, the most efficient two turn two suction device can further reduce the emissions of 40%, 50 PPM SO₂Emissions, which mainly depends on the feed gas and plant layout.A turn a burning sulfur absorption device operating experience proves that vitamin k - 701 LEAP5 ™ highly reactive.

Combined with vitamin k and vitamin k - 701-69 of highly active advantages, to design a new 3:1 device provides the conditions,SO in this new device feed gas_{2 emissions can be reduced to 20 to 50 PPM}(0.1-0.25 kg SO₂MT/H.₂SO₄, 0.2 0.5 LBS/ST).The existing device adopts reduced SO vitamin k - 701₂Emissions, provides an attractive alternative, namely no longer need to spend money to purchase caustic scrubber or hydrogen peroxide.Even as the device is equipped with exhaust gas scrubber, vitamin k - 701 is also reduce washing chemicals consumption way of the economy.

reference

1. Jensen - Holm, h. (1996). The New Catalyst Options for Improved Performance of sulfuric Acid. The Plants sulfur '96, pp. 235-49, British sulfur Publishing, London.
2. Jensen - Holm, h. and Hansen, l. (1997). Remained negligible Performance Improvements in sulfuric Acid the Plants Using vitamin k - 69 Catalyst. Sulfur '97, pp. 193-206, British sulfur Publishing, London.
3. Lapina O.B., Bal 'zhinimaev, b.s., Boghosian, s., Eriksen, k. m. and Fehrmann, r. (1999). The Catalysis Today, 51, 469-479.