György Pölczmann

Sustainable production of bioparaffins

Most prevalent fuels of Diesel engine vehicles are the gas oils produced on crude oil bases. According to some disadvantages of fatty acid-methyl-esthers (biodiesels), bioparaffins (mainly isoparaffins) are able to substitute them partially or totally. The production of bioparaffins can be carried out on a wide raw material base. This means the natural triglycerides (different origin non-food vegetable oils, “brown fat” of sewage works, fat of protein processing, algae oils, etc.), lignocelluloids etc.. In this paper catalytic systems (NiMo/Al2O3; Pt/SAPO-11; Pt/AlSBA-15) for the production of bioparaffins from different triglycerides (oils and fats) and high molecular weight Fischer-Tropsch (heavy) hydrocarbons (produced from biobased synthesis gas) are introduced. After the proper pretreatment of natural triglyceride feedstocks the suggested two-step technologies (deoxygenation and isomerisation) are able to produce nand isoparaffins with yield that approaches the 93-99 % of the theoretical value. Properties of the two bioparaffin fractions produced with these methods satisfy the requirements of EN 590:2009+A1:2010 standard. Their cetane number is in the range of 65-75, which makes it possible to blend lower quality blending components in higher quantity, which is the source of significant profit increase. The integration possibilities of the suggested technologies in to crude oil refineries are introduced, too.

Investigation of isomerisation of light naphtha fractions

In our experimental work the transformability of C6 cycloparaffin components containing typically hydrocarbon mixtures with high n-paraffin and/or cycloparaffin concentration as well as industrial like light naphtha fractions convertible and the kinetic investigation of individual “key” hydrocarbons effect among and on each other in binary mixtures – applying parameters similar to industrial conditions – and also the further applicability of the results were studied. Experiments were carried out on Pt/sulfated-zirconia catalyst at 150-200 °C temperature, 12-30 bar total pressure, 1:1-2:1 H2-hydrocarbon molar ratio, 1.0-4.0 h -1 liquid hourly space velocity in the laboratory scale reactor system for the kinetic investigation of individual hydrocarbons and binary mixtures. The reaction rate, reaction order and apparent activation energies of the individual hydrocarbons were studied as well as in its binary mixtures the change of the individual hydrocarbons reaction rate and the apparent activation energies. Isomerization of individual cycloparaffins and cycloparaffin rich light naphtha fraction was also studied.

Catalytic conversion of Fischer-Tropsch waxes

Nowadays, the application of fuels and lubricants produced from renewable feedstocks has come to the front because of serious environmental problems and ambiguity of crude oil supply. In this paper mesoporous Pt/AlSBA-15 catalysts with different platinum contents were investigated and it was found that catalysts having 0.5 wt. % platinum showed the best results in the production of gas oil and base oil fractions with high isoparaffin content from Fischer-Tropsch wax. The selectivity of the target product fractions was high, and based on these facts the selective isomerization of the FischerTropsch wax can be a new application area of the Pt/AlSBA-15 catalyst.

Hydrodearomatization of sulphur and nitrogen containing gas oils on bimetallic catalysts

Abstract The main motivation of the development of hydrodearomatization of middle distillate is the growing demand for high quality (low sulphur-, nitrogen- and aromatic content) gas oils for transportation and for economical production of light olefins (ethylene, propylene). The results of hydrodearomatization of different sulphur and nitrogen containing real gas oils from Hungarian and Russian crudes on Pt,Pd/USY zeolite, amorphous Pt,Pd/SiO 2 -Al 2 O 3 and Pt,Pd/Al 2 O 3 catalysts with different ratio of Pd/Pt are presented. Additionally, the effect of sulphur and nitrogen contents of feeds and process conditions on HDA, HDN and HDS activities was studied. The Pt-Pd/USY catalyst having Pd/Pt atomic ratio of 4:1 was the most active in hydrodearomatization of high sulphur and nitrogen containing feeds. At favourable process conditions excellent quality (sulphur: 1–6mg/kg, nitrogen: 1–3 mg/kg and aromatic content: 5–15%, cetane number: 53–56) diesel fuel blending component can be produced with high gas oil yield, which is an excellent feed for steam cracking either.

Investigation of storage stability of gas oils containing waste originated biodiesel

One of the pillars of sustainable development is the mobility, which has significant energy demand. Nowadays in Europe the demand for diesel fuel continuously growing, while the demand for gasoline decreases slightly. Currently, the biodiesel is the biofuel which is blended into the gas oil with the highest amount in case of Diesel engines, which can be produced from different, even waste-derived triglycerides (with transesterification with alcohol). Due to the adverse properties of biodiesel the storage stability of biodiesel/diesel blends have to be examined in detail. In our experimental work we studied the changes in the qualities of biodiesels produced from vegetable oil which contained various waste cooking oil (waste-derived component) share (10, 30, 50 %), and its 7 and 10 % blends with gas oil in case of long-term (more than 150 weeks) storage. We found that with the increasing the proportion of used cooking oil in the vegetable oil used as raw material for biodiesel the oxidation reactions took place in greater amount during the storage of the biodiesel product. Biodiesel made from vegetable oils containing 10 % used cooking oil was the most applicable for blending; in case of using higher proportion it is very necessary to use further amount of antioxidant additives to minimize the degradation. The test results suggest that without the addition of additives the biodiesels are not allowed to store longer than six months, and the diesel-biodiesel blends are not allowed to store longer than 1 year. We established mathematical relationships which describe well the relationship between the Rancimat induction period and the kinematic viscosity and the acid number in case of the investigated biodiesels.