9 research outputs found
Use of residual soapstock from the refining of edible vegetable oils to make biodiesel.
Se estudia un procedimiento para la obtención de Biodiesel a
partir de las “Oleínas”. Biodiesel es un producto capaz de sustituir
al combustible Diesel ordinario que se obtiene del petróleo y que
consiste en una mezcla de ésteres metílicos de ácidos grasos.
Las oleínas son unos residuos que resultan del proceso de refina-
do de aceites vegetales para su uso alimentario y se componen
de una mezcla de triglicéridos y ácidos grasos libres, con un con-
tenido de estos últimos componentes superior al 50% . El merca-
do de oleinas es fluctuante, con lo que en ocasiones surge el
problema de su eliminación. Como resultado del trabajo efectua-
do se define un proceso de obtención que consta de las siguien-
tes etapas:
1. Esterificación de los ácidos libres de la Oleína con meta-
nol, aplicando catálisis ácida, centrifugando el producto obtenido
y separándolo de la fase metanol-ácido. En ésta etapa se obtiene
un producto que contiene alrededor de un 70% de metil- esteres.
2. Transesterificación de los triglicéridos presentes en el
producto esterificado con metanol, aplicando catálisis alcalina. El
producto obtenido, previamente separado de la fase metanol-
agua, contiene alrededor de un 90% de metil-esteres.
3. Purificación del producto resultante de las etapas 1 y 2 ,
por rectificación a vacío. El producto destilado tiene un contenido
en metil-esteres superior al 98%.A procedure to obtain Biodiesel from “Oleinas” is studied.
Biodiesel is a suitable product to replace diesel oil currently used
to power the Diesel engines. It consists of a mixture of methyl
esters of the fatty acids presents as triglycerides in vegetables oils
(olive, sunflower, soya, rape oils). As a result of the refining of
these oils for their use as food, a waste product is formed, the
“oleinas” (acidulated soapstock). The oleinas consist of a mixture
of triglycerides and free fatty acids, the latter amounting to 50% or
more of the mixture and are subject to a fluctuating market,
therefore it exist at times a problem for their disposal.
In our research work we have tried to obtain biodiesel from
oleinas. The process resulting from our experimental work is as
follows:
1. Sterification of the free fatty acids with methanol, by acid
catalysis, centrifuging the reaction product and removal of the
acid-methanol phase. Drying of the latter. At this stage we have a
product containing about 70% of methyl esters.
2. Transesterification of the triglycerides present in the
sterified product with methanol by alkaline catalysis, washing the
reaction product with a water methanol solution. Centrifuging and
removal of the water-methanol phase. At this stage a biodiesel
product is obtained containing about 90% of methyl esters.
3. Fractional vacuum distillation of the 90% biodiesel gives a
final product with a methyl esters content higher than 98%
Predictive factors of six-week mortality in critically ill patients with SARS-CoV-2: A multicenter prospective study.
The objective of the study is to identify the risk factors associated with mortality at six weeks, especially by analyzing the role of antivirals and munomodulators. Prospective descriptive multicenter cohort study. 26 Intensive care units (ICU) from Andalusian region in Spain. Consecutive critically ill patients with confirmed SARS-CoV-2 infection were included from March 8 to May 30. None. Variables analyzed were demographic, severity scores and clinical condition. Support therapy, drug and mortality were analyzed. An univariate followed by multivariate Cox regression with propensity score analysis was applied. 495 patients were enrolled, but 73 of them were excluded for incomplete data. Thus, 422 patients were included in the final analysis. Median age was 63 years and 305 (72.3%) were men. ICU mortality: 144/422 34%; 14 days mortality: 81/422 (19.2%); 28 days mortality: 121/422 (28.7%); 6-week mortality 152/422 36.5%. By multivariable Cox proportional analysis, factors independently associated with 42-day mortality were age, APACHE II score, SOFA score at ICU admission >6, Lactate dehydrogenase at ICU admission >470U/L, Use of vasopressors, extrarenal depuration, %lymphocytes 72h post-ICU admission 6, Lactate dehydrogenase at ICU admission >470U/L, Use of vasopressors, extrarenal depuration, %lymphocytes 72h post-ICU admission 470U/L, Use of vasopressors, extrarenal depuration, %lymphocytes 72h post-ICU admission Age, APACHE II, SOFA>value of 6 points, along with vasopressor requirements or renal replacement therapy have been identified as predictor factors of mortality at six weeks. Administration of corticosteroids showed no benefits in mortality, as did treatment with tocilizumab. Lopinavir/ritonavir administration is identified as a protective factor