After going through the references from higher texts (Vedic) I have understood that a sanyAsin CANNOT perform the Vedic yajnas/sacrifices.
Let us understand this with various references.
The whole of Vedas revolve around sacrifices and they are so important that the grhya and srauta sutras are written for yajna and domestic rituals.
However, the sanyasa tradition totally neglects the vedic recommendations and renounce fire totally along with wife and family. In some tradition the thread and shikhA is also renounced. This is not what the Vedas advocate,
Let us see some of the important quotes,
Vedas say that performing yajnas is the main duty of every man. The life given to him by god is for purpose of following life as per vedas and perform yajnas whenever possible. Sat. Brah. 22.214.171.124
And, accordingly, in that he is born as (owing) a debt to the gods, in
regard to that he satisfies (ava-day) them by sacrificing; and when he
makes offerings in the fire, he thereby satisfies them in regard to
that (debt): hence whatever they offer up in the fire, is called
avadânam (sacrificial portion)
Yajna is a boat which helps one sail smoothly in the world. Ai. Brah. 1.3.2
It is also said that the heavenly gods attained their divine godhood by performing sacrifices. Sat. Brah. 126.96.36.199
- The sacrifice fled away from the gods. The gods called out after it, 'Listen (a-sru) to us 2! come back to us!' It replied, 'So be it!'
and returned to the gods; and with what had thus returned to them, the
gods worshipped; and by worshipping with it they became the gods they
The purusha suktam of rigveda mentions gods themselves as sacrificers,
yajnena yajnam ayajanta devaha tani dharmani pradhamanyasan te ha
nakam mahimanas sacante yatra purve sadhyah santi devaha
Unmarried man has no right for vedic sacrifices. The brahmachari (student) has very limited right to perform agni-adhAna which is the preparation for agnihotra after marriage.
It is mandatory for vedic yajna to have the wife accompanying him during the ritual.
Most of the vedic fire rituals contain a segment called patnIsamyAja which is related to the wife.
In the Isti yAgas, there is a portion patnIsamyAja which cannot be done without a wife.
In the highly celebrated soma yAga, there is a avabhrtha rite which is not possible without the wife.
In the chAturmAsya yaga also there are rites related to the wife. In the Varunapraghasas also wife is mandatory for some of the rites.
She takes the position at the sacrifice at the prescribed vedi.
Wife obtains half part of the yajna as stated in brAhmana.
ardho ho vA esha yajnasya yat patnI --- Sat.Brah.
Also, gods do not take ahuti from an unmarried/wifeless person hence sanyasins, bachelors, widowers CANNOT perform vedic yajnas.
na vai apatnIkasya hastAt deva balim grhanti - Sat. Brah. 188.8.131.52
Even for the agnihotra sacrifices, it is mandatory to have a wife else it cannot be performed.
From the above statements it is clear that vedic yajnas are not possible in absence of spouse.