FIELD OF THE INVENTION

The present disclosure is related to the field of diesel compositions and to manufacturing diesel composition having improved properties. More specifically, it is related to diesel compositions comprising at least three components, a fossil diesel component, a renewable paraffinic diesel component and an oxygenate, providing benefits with diesel emissions. It is also related to a method for producing said compositions. Further, it is related to use of a combination of renewable paraffinic diesel component and oxygenate as fuel blending components to fossil fuel.

BACKGROUND

Oxygenates have been studied as diesel components for fossil fuels, before renewable diesels rose attention. Typically, an improvement achieved with an oxygenate in one of diesel characteristics, for example higher cetane number, better cold properties or reduced emissions, have been compromised by a deficit in another. For example, certain ethers combined with fossil diesel have been shown to reduce particulate matter (PM) emissions, but such an advantage is burdened with an increase in NOxemissions.

On the other hand, recently the regulations and concern for environment have encouraged the use of renewable fuels. Oxygenates have been studied as components in renewable diesel or biodiesel as well. Publication WO2012074925 envisions a composition comprising renewable diesel, which they call RHE, and oxygenates. Both components are discussed very generally. As possible oxygenates, it discusses esters, ethers and/or hemiacetals comprising alcohols, polyols or combinations thereof. However, in experimental part, no actual tests are conducted. Publication WO2012074925 also lists several references to measuring techniques and possible outcome thereof.

Publication EP1398364 claims a composition comprising 0.1-99% paraffinic diesel component, 0-20% compound containing oxygen and the rest can be regular crude oil based diesel. Said component containing oxygen may be selected from aliphatic alcohols, ethers, fatty acid esters, water or mixtures thereof. A blend of fossil diesel fuel 40% and hydrogenated and isomerized tall oil fatty acids (TOFA) 60% was characterized. In another example, a 70/30 blend of fossil diesel fuel and an ester was compared to another blend, 70/30, of fossil diesel and TOFA, which showed how ester seemed to affect an increase in both NOxand PM emissions. The desired result in reduced emissions was obtained only by the two component blend of fossil diesel and hydrogenated and isomerized TOFA. No results from blends comprising three components were presented.

Thus, there is a need to provide further diesel fuel compositions comprising oxygenates while reducing harmful effects typically related thereto.

SUMMARY

As the first aspect, here is provided a diesel composition comprising:a) fossil diesel componentb) oxygenate component from 10 vol-% to 40 vol-%, preferably from 10 vol-% to 30 vol-% of the total fuel composition volume, whereini. said oxygenate is a monoether having molar mass from 128 to 300 g/mol, andii. said oxygenate is of structure
R1—O—R2(formula 1),in which formula R1and R2are same or different and selected from C1-C15alkyl groups, andc) renewable paraffinic diesel component from 10 vol-% to 30 vol-% of the total fuel composition volume,wherein the sum of said oxygenate component and said renewable paraffinic diesel component is from 26 to 70 vol-%, preferably from 30 vol-% to 50 vol-% of the total fuel composition volume.

Against expectations, compositions containing renewable paraffinic diesel fuel from 10 to 30%, an oxygenate component of formula 1 from 10 to 40% and fossil diesel, have been shown to reduce PM emissions. Without being bound to a theory, the surprising reduction in PM emissions with this specific blend is considered to be due to synergistic effect of the renewable paraffinic diesel component and the oxygenate component present in said composition.

According to a preferred embodiment, composition comprises renewable paraffinic diesel fuel from 10 to 30 vol-%, a monoether oxygenate component 10-40 vol-% and regular (fossil) diesel from 30 to 74 vol-%, wherein the renewable paraffinic diesel component is produced by a hydrogenation process of vegetable oil, animal fat, fish fat, fish oil, algae oil, microbial oil and/or wood and/or other plant based oil as well as recyclable waste and/or residue or a combination thereof, or preferably by a hydrodeoxygenation-isomerization process thereof, which have shown excellent performance in emission experiments. Without binding to any theory, the results indicate that the characteristic paraffin profile of the renewable paraffinic diesel component acts synergistically with the monoether having molar mass from 128 to 300 g/mol providing a beneficial effect on the cetane number in fuel blends.

The oxygenate component is advantageously selected to provide desired characteristics to the blend. Monoethers studied for their properties in blends showed some variability as to cetane number and cold properties. Depending on the desired diesel characteristics, selections among monoethers could be made. Symmetrical and unsymmetrical straight chain monoethers provide increase in cetane number in addition to desired emission effects. According to unexpected results in emission tests, the most preferable oxygenate is di-n-pentyl-ether (DNPE).

The advantage of the novel composition is that the blend can decrease particulate matter (PM) emissions without penalty on NOx emissions. It is generally known that oxygenates, such as ethers can decrease the PM emissions of regular diesel, but simultaneously the NOx emissions increase. Paraffinic diesel is capable of reducing PM emissions significantly without compromising the advantage by heavily increased NOx emissions.

According to the second aspect, here is provided a method for producing a blend fuel, wherein the renewable paraffinic diesel component is produced from a renewable feedstock by a process selected froma) hydrogenation or deoxygenation of vegetable oil, animal fat, fish fat, fish oil, algae oil, microbial oil and/or wood and/or other plant based oil as well as recyclable waste and/or residue or combinations thereof to obtain a paraffinic C9-C24hydrocarbon fraction, which is optionally subjected to isomerization, orb) gasification of biomass to produce syngas and production of paraffins from said syngas by Fischer-Tropsch synthesis to obtain a paraffinic C9-C24hydrocarbon fraction, orc) a combination thereof,and blending the renewable paraffinic diesel component thereby obtained, with an monoether oxygenate component having molar mass from 128 to 300 g/mol; and with fossil diesel component to obtain a diesel composition as described above.

According to the third aspect, herein is provided use of a monoether oxygenate having molar mass from 128 to 300 g/mol and renewable diesel as fuel blending components to fossil diesel component to obtain a fuel composition, wherein the total fuel composition comprises from 10 vol-% to 40 vol-% of monoether oxygenate, and from 10 vol-% to 30 vol-% renewable paraffinic diesel and the sum of said oxygenate component and said renewable paraffinic diesel component is from 26 to 70 vol-%, preferably from 30 vol-% to 50 vol-%, wherein vol-% is calculated of the total fuel composition volume.

An advantage achieved by the present fuel composition, method and use is the decrease in PM emissions. As evidenced by the examples, the oxygenate content of fuel compositions could be increased with composition containing said components in said proportions, but PM emissions decreased significantly while NOxemissions stayed practically the same or were increased considerably less than expected. The advantageous effect was observed in particular in blends comprising fossil fuel.

According to a further aspect, in composition or use the oxygenate component or raw material therefor, is derived from biomass, whereby it can be considered as renewable component. Together with renewable paraffinic diesel component it contributes to the percentage of renewable, non-fossil components in the total fuel composition.

