Fig.1. Processed granules of the absorber NIAP-02-05, unloaded from the second stage of desulphurization, split in sections: a – transverse, b – longitudinal Absorbers OOO NIAP-KATALYZATOR Currently, NIAP-KATALYZATOR LLC is a leading Russian manufacturer of
desulphurization catalysts for industries that receive synthesis gas from natural gas.
Its catalyst production produces several types of absorbers for different operating conditions
and consumer requirements. Zinc composites NIAP-02-02 (tablets) and NIAP-02-05 (extrudates)
were designed for the temperature range of 300–390°C. NIAP-02-05 works stably at temperatures
up to 450°C, while zinc-copper composites NIAP-02-03 ( extrudates ) and NIAP-02-04 (tablets) are
designed for a temperature range of 150–350°C.
In 2017, the production of absorbers exceeded 400 tons.
In table. 2 shows some characteristics of zinc catalysts of OOO NIAP-KATALYZATOR
[13-14].
There are two important differences from those produced earlier: a) zinc-containing raw
materials for their preparation are more expensive zinc white, an essential feature of which is the
practical absence of harmful impurities, primarily lead; b) an intermediate stage in their production
is the production of basic zinc carbonate; this significantly reduces the size of the ZnO crystallites,
which makes it possible, in particular, to obtain finer zinc oxide particles during grinding and thus
improves the sulfur absorption, as well as the dynamic characteristics of the ZnS formation process.
The use of zinc carbonate in the preparation of zinc scavengers was first described in [15].
Table 2 Brand Specific surface, m 2 /g Porosity, % Sulfur capacity, % NIAP-02-02 34
35
25
NIAP-02-05 56
54
32
An important role in the formation of a stable structure of the absorber is played by the
addition of a small amount (5–7 wt %) of MgO during the production of extrudates. It was shown in
[14] that the size of ZnO particles (about 300 Å) and sulfur capacity are retained during the
industrial operation of absorbers due to MgO.
With the current quality of natural gas, a full load of a modern absorber (if it is properly
operated) lasts for decades. Such runs of the NIAP-02-05 absorber took place, for example, in NAK
Azot JSC (Evrokhim company), Novomoskovsk, and Metafrax OJSC (Gubakha).
In addition, back in the 1970s, it was found that when the sulfur content is less than 10
mg/m
3
, hydrogenation
and hydrodestruction organosulfur compounds, typical of natural gas,
completely occur in the already sulphurized frontal layer of the absorber.
